Electronic conveyor for molten metal with elevated pouring tube

ABSTRACT

An improved electromagnetic trough for conveying and delivering molten metal or metal alloys, for example, for casting having a melting or holding furnace, an associated electromagnetic trough with a refractory upwardly sloping body, an electromagnetic travelling field inductor extending along its length for conveying the material up the trough, a wall extending across the trough body at the upper end thereof and closing the same, and a refractory tube located adjacent that wall at the upper end of the trough, passing through the floor for delivering molten metal with the upper end of the tube extending above the level of the floor to prevent dribble as the residual melt slowly flows away delayed by irregularities in the brickwork lining.

[ 1 May 13, 1975 ELECTRONIC CONVEYOR FOR MOLTEN METAL WITH ELEVATED POURING TUBE [75] Inventor: Hans Erwin Gerbig, Deutscher Staatsangehoriger, Germany [73] Assignee: AEG-Elotherm GmbI-I, Remscheid,

Germany [22] Filed: Sept. 14, I973 [21] Appl. No.: 397,328

[30] Foreign Application Priority Data Sept. 30, 1972 Germany 2248052 [52] U.S. Cl. 222/372; 266/38; 417/50 [51] Int. Cl 822d 37/00 [58] Field of Search 222/372, 566; 417/50; 164/63; 266/38 [56] References Cited UNITED STATES PATENTS 3,044,499 7/1962 Frerich 222/566 UX 3,558,121 l/l97l Lenne 164/63 X 3,610,600 10/1971 Schnake 222/372 UX 3,754,634 8/1973 Gerbig 417/50 X FOREIGN PATENTS OR APPLICATIONS 904,526 8/1962 United Kingdom 222/559 UX Primary ExaminerRobert B. Reeves Assistant Examiner-David A. Scherbel Attorney, Agent, or Firm-Cushman, Darby & Cushman [57] ABSTRACT An improved electromagnetic trough for conveying and delivering molten metal or metal alloys, for example, for casting having a melting or holding furnace, an associated electromagnetic trough with a refractory upwardly sloping body, an electromagnetic travelling field inductor extending along its length for conveying the material up the trough, a wall extending across the trough body at the upper end thereof and closing the same, and a refractory tube located adjacent that wall at the upper end of the trough, passing through the floor for delivering molten metal with the upper end of the tube extending above the level of the floor to prevent dribble as the residual melt slowly flows away delayed by irregularities in the brickwork lining.

2 Claims, 2 Drawing Figures NA W/N/N/NN/W/W/W/WAVWM FZRTENTED MAY 1 31975 INNNN/WNNN/W/W/WAV/WM ELECTRONIC CONVEYOR FOR MOLTEN METAL WITH ELEVATED POURING TUBE The invention relates to casting equipment for pouring metal or metal alloy melts of the type having a melting or holding furnace associated with an electromagnetic conveying trough or launder proceeding from the furnace vessel, the conveying trough having a refractory upwardly sloping body and an electromagnetic travelling field inductor extending along its length for conveying the material up the trough.

Equipment of this kind is described for instance in U.S. Pat. No. 3,6l2,720. In this equipment an electromagnetic travelling field propels the liquid melt from the furnace vessel in an open stream up the sloping trough contrary to gravity, the melt pouring into the casting mold from the upper end of the trough. For the purpose, among the upper end of the trough. For the purpose, among other objects, of discharging an exactly predetermined quantity of melt, irrespectively of the level of the melt in the furnace, the windings of the travelling field inductor are divided into a component winding which is permanently energized at the bottom end of the trough, and which has the effect of lifting the melt to a predetermined point up the sloping trough, and into a second component winding which is energized only for the duration of the pour, and which is lo cated at the upper end of the trough. This known type of casting equipment delivers the melt in very satisfactorily metered quantities However, in such equipment a troublesome phenomenon, which becomes worse as the lining of the pouring spout at the upper end of the trough is progressively eroded or fouled, is the tendency to dribble until residual melt, delayed by irregularities in the brickwork lining, has slowly flowed away. For many applications, for example, for widely spaced pours in which there is time to wait for dribbling to cease, this phenomenon may frequently not matter. However, if a casting machine, for instance a pouring wheel or pouring conveyor, is to be supplied with relatively small weights of melt at relatively rapid intervals, then dribbling is a major nuisance.

It is therefore an object of the present invention to provide improved casting equipment comprising a melting or holding furnace and an associated electromagnetic conveying trough or launder integrated with a furnace vessel for pouring metal or metal alloy melts, in which dribbling of residual melt from the pouring spout at the upper end of the trough when a pour has been completed is substantially suppressed, and which also permits an even better metering precision during the casting operation to be achieved than is possible in conventional equipment.

In casting equipment according to the invention these objects are achieved by forming the refractory body of the trough at its upper end with a wall extending across the width of the trough and thus closing the effective open cross section of the trough, and by pro viding, in proximity with this terminal wall, a refractory pouring tube which passes through the bottom of the trough and of which the upper end projects beyond the level of the adjacent floor of the trough, whereas its length is sufficient to ensure that the melt will issue from the pouring tube in an unbroken jet. If, as is conventional, the travelling field inductor is located underneath the refractory body of the trough the floore of the trough is arranged from a point corresponding to the upper end of the travelling field inductor to continue sloping upwards in the direction towards the terminal wall.

In a preferred embodiment of the inventon a channel traverses the bottom of the trough for the reception of the pouring tube which is secured to the bottom of the trough at the upper end of the channel. Conveniently the pouring tube may be connected to a sleeve of refractory material, this sleeve being itself adhesively bonded to the upper end of the channel so that its upper end is flush with or projects above the neighboring level of the floor of the trough. The invention will now be more particularly described with reference to the drawings in which:

FIG. 1 is a schematic longitudinal section of casting equipment according to the invention. FIG. 2 on a larger scale shows those particular parts of the equipment which concern the present invention.

Referring to FIGS. 1 and 2, a furnace vessel 3 (only partly shown in Figure 1) closed by cover plate 2 rests on foundations 1. The body of the furnace is laterally connected to the ascending refractory body 4 of an electromagnetic conveying trough or launder. Disposed underneath the body 4 of the trough, which is likewise upwardly closed by a cover 5, is an inductor 6 for the generation of a travelling electromagnetic field. The windings of the inductor are divided into a lower winding 7 which begins at the furnace vessel 3 and a second upper winding 8 which in continuation of the first extends to the upper end of the trough. The connections 9 for feeding the windings enter where the two windings meet.

In the region 10 of the last inductor pole at the upper end of the trough, the floor 1 1 of the trough flattens out into roughly the horizontal. Moreover, the upper end of the body of the trough 4 is covered by bridge 12 connecting the sidewalls of the trough and consisting of a rammed refractory composition. This bridge member has an opening closed by a box-like cover 13.

Contrary to conventional electromagnetic conveying troughs for pouring metered volumes of melt, the refractory body 4 of the trough is provided at its upper end with a terminal wall 14 extending across the longitudinal axis of the trough. In proximity with this wall a refractory pouring tube 16 penetrates the bottom 15 of the trough. This pouring equipment is intended for instance for pouring a melt into casting molds 17 which are conveyed to the equipment on a pouring conveyor indicated at 18 in Figure 1.

Roughly the portion in Figure 1 which is enclosed by the circle 19 and which comprises the pouring tube 16 as well as the terminal wall 14, is shown on a larger scale in Figure 2.

The pouring tube 16 of which the top 20 projects beyond the level of the neighboring floor 11 of the trough is embraced by a sleeve 22. The pouring tube 16 and the sleeve 22 are contained in a channel 23 which traverses the bottom 15 of the trough, the top of the sleeve being roughly flush with the adjacent surface 11' of the floor of the trough. The tube and its sleeve are bonded for instance adhesively to the bottom 15 only at the top of the channel 23 so that the development of thermal stresses between the bottom 15 of the trough and the pouring tube 16 is substantially avoided. Below the sleeve 22 the wall of the channel is formed by a refractory tube 24 which limits the extent of the rammed composition forming the bottom of the trough, and

which supports thebottom end of the sleeve 22. Finally, as will be understood by reference to Figure 2, the body 4 of the trough is so contrived that between the upper end 25 of the travelling field inductor 6 and the terminal wall 14 the bottom surface 11' of the trough still continues to rise towards the terminal wall 14.

The described pouring equipment is operated as follows:

Throughout the entire process of casting the bottom winding 7 of the travelling field inductor remains energized. The travelling electromagnetic field which it creates propels melt from the furnace vessel 3 up the slope of the trough to the point where the second winding 8 begins. This causes a stationary layer 26 of melt which heats the body 4 of the trough and which does not itself cool because it remains in permanent mass exchange with the charge 27 in the interior of the furnace vessel 3, to be maintained.

The individual pour is initiated by the upper component winding 8 being connected to voltage, and thereby causing the column of melt extending part of the way up the trough to be propelled further to the upper end of the trough where it can flow out through the pouring tube 16. The intensity of the travelling field produced by the inductor is so controlled that the propelling power of the trough exceeds the maximum rate at which the melt can leave through the pouring tube 16. Under these conditions the exposed surface of the melt will quite soon, i.e. usually immediately after pouring begins, assume a position in the trough such as that indicated by the line 28, the depth of the layer depending primarily upon the performance of the trough. Since the height h of the melt surface 28 above the upper end of the pouring tube 16 (cf. Figure 2) will thus be kept substantially constant, the rate at which the melt flows through the pouring tube 16 likewise remains substantially constant for the major part of the pour. The pour is terminated by switching off the upper component winding 8 of the inductor -controlled by a suitable time switch when the major proportion of the melt within range of this component part 8 of the winding higher up in' the trough will flow rapidly back into the furnace vessel 3, accelerated by gravity down the slop of the floor 11' of the trough, thereby cutting off the further flow of melt through the pouring tube 16. Residual melt which runs away more slowlyby virtue of delaying irregularities in the body of the trough 4 cannot cause the pouring tube 16 to dribble because the upper end 20 of the tube 16 projects above the neighboring floor level 11 of the trough.

The length of the pouring tube is so chosen according to the nature of the melt that the teeming melt will leave the bottom end of the tube 16 in the form of a continuous jet.

Many changes and modifications of the above embodiment of the invention can be carried out without departing from the scope thereof. Accordingly, that scope is intended to be limited only by the scope of the appended claims.

What is claimed is:

1. ln casting equipment for pouring melts, of the type having a furnace associated with an electromagnetic conveying trough proceeding from said furnace vessel, said conveying trough having a refractory body upwardly sloping from said vessel, and an electromagnetic travelling field inductor extending along its length below said refractory body, the floor of the trough rising in the direction of a terminal wall from a point corresponding to the upper end of said conductor, the improvement comprising said terminal wall extending across the width of the trough and closing the effective open cross section of the trough, and a refractory pouring tube which passes through the trough bottom in proximity to said wall and of which the upper end projects above the level of the adjacent floor of said trough.

2. In casting equipment for pouring melts, of the type having a furnace associated with an electromagnetic conveying trough proceeding from said furnace vessel, said conveying trough having a refractory body upwardly sloping from said vessel, and and electromagnetic travelling field inductor extending along its length, the improvement wherein said refractory body of the trough has an upper end provided with a wall extending across the width of the trough and closing the effective open cross section of the trough, and a refractory pouring tube which passes through the trough bottom in proximity to said wall and of which the upper and projects above the level of the adjacent floor of said trough, said trough having a channel extending through the bottom thereof for the reception of said pouring tube which is connected at the upper end of the channel to the trough bottom, and a sleeve of a refractory material connected to said pouring tube and adhesively bonded to the top of the channel so that its upper end is at least flush with the neighboring part of the trough floor, the wall of the channel below the bottom end of the sleeve being formed by a refractory tube of which the upper end supports the sleeve. 

1. In casting equipment for pouring melts, of the type having a furnace associated with an electromagnetic conveying trough proceeding from said furnace vessel, said conveying trough having a refractory body upwardly sloping from said vessel, and an electromagnetic travelling field inductor extending along its length below said refractory body, the floor of the trough rising in the direction of a terminal wall from a point corresponding to the upper end of said conductor, the improvement comprising said terminal wall extending across the width of the trough and closing the effective open cross section of the trough, and a refractory pouring tube which passes through the troUgh bottom in proximity to said wall and of which the upper end projects above the level of the adjacent floor of said trough.
 2. In casting equipment for pouring melts, of the type having a furnace associated with an electromagnetic conveying trough proceeding from said furnace vessel, said conveying trough having a refractory body upwardly sloping from said vessel, and and electromagnetic travelling field inductor extending along its length, the improvement wherein said refractory body of the trough has an upper end provided with a wall extending across the width of the trough and closing the effective open cross section of the trough, and a refractory pouring tube which passes through the trough bottom in proximity to said wall and of which the upper and projects above the level of the adjacent floor of said trough, said trough having a channel extending through the bottom thereof for the reception of said pouring tube which is connected at the upper end of the channel to the trough bottom, and a sleeve of a refractory material connected to said pouring tube and adhesively bonded to the top of the channel so that its upper end is at least flush with the neighboring part of the trough floor, the wall of the channel below the bottom end of the sleeve being formed by a refractory tube of which the upper end supports the sleeve. 